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Li B.,University of Nebraska Medical Center | Ricordel I.,Institute National Of Police Scientifique | Schopfer L.M.,University of Nebraska Medical Center | Baud F.,University Paris Diderot | And 5 more authors.
Toxicological Sciences | Year: 2010

Studies in mice and guinea pigs have shown that albumin is a new biomarker of organophosphorus toxicant (OP) and nerve agent exposure. Our goal was to determine whether OP-labeled albumin could be detected in the blood of humans exposed to OP. Blood from four OP-exposed patients was prepared for mass spectrometry analysis by digesting 0.010 ml of serum with pepsin and purifying the labeled albumin peptide by offline high performance liquid chromatography. Dimethoxyphosphate-labeled tyrosine 411 was identified in albumin peptides VRY411TKKVPQVSTPTL and LVRY411TKKVPQVSTPTL from two patients who had attempted suicide with dichlorvos. The butyrylcholinesterase activity in these serum samples was inhibited 80%. A third patient whose serum BChE activity was inhibited 8% by accidental inhalation of dichlorvos had undetectable levels of adduct on albumin. A fourth patient whose BChE activity was inhibited 60% by exposure to chlorpyrifos had no detectable adduct on albumin. This is the first report to demonstrate the presence of OP-labeled albumin in human patients. It is concluded that tyrosine 411 of human albumin is covalently modified in the serum of humans poisoned by dichlorvos and that the modification is detectable by mass spectrometry. The special reactivity of tyrosine 411 with OP suggests that other proteins may also be modified on tyrosine. Identification of other OP-modified proteins may lead to an understanding of neurotoxic symptoms that appear long after the initial OP exposure. © The Author 2010. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org.

Haned H.,University Claude Bernard Lyon 1 | Egeland T.,University of Oslo | Pontier D.,University Claude Bernard Lyon 1 | Pne L.,Institute National Of Police Scientifique | And 2 more authors.
Forensic Science International: Genetics | Year: 2011

Allele drop-out is a well known phenomenon that is primarily caused by the stochastic effects associated with low quantity or low quality DNA samples. Recently, new interpretation models that employ the use of logistic regression have been utilised in order to estimate the probability of drop-out. The model parameters are estimated using profiles from samples of extracted DNA diluted to low template levels in order to induce drop-out. However, we propose that this approach is over-simplistic, because several sources of variability are not taken into account in this generalised model. For example, in real-life, small (discrete) crime-stains are analysed where cells are (or were) intact. The integrity of the paired chromosomes of the diploid cell is preserved. In extracted DNA that is diluted to low template levels, we argue that the paired-chromosome integrity is lost. This directly affects the outcome of the logistic model. To date, current experimentation procedures are more akin to haploid cells and thus, different logistic models are needed for haploid and diploid cells. In order to simplify the methodology to estimate the multiple logistic regressions, we propose the use of a simulation model of the entire process associated with the analysis of STR loci, as a supplement to the purely experimental approach to support the validation of new methods. We illustrate with an evaluation of some features of the logistic model proposed by Gill et al., 2009 [12] and discuss alternative models. © 2010 Elsevier Ireland Ltd.

Agency: Cordis | Branch: FP7 | Program: CP | Phase: SEC-2010.1.3-3 | Award Amount: 4.59M | Year: 2011

The objective with the EMPHASIS project is to develop a system for detecting ongoing illicit production of explosives and improvised explosive devices (IEDs) in urban areas. The EMPHASIS system will be composed of networked sensors. Area sensors, strategically positioned, for the monitoring of explosives or precursors to explosives in the vapour phase will be used. Static sensors, positioned in the sewer, for the monitoring of the sewage for indicative traces will also be used. The detectors will be connected in a network and the total gathered data will be fused and evaluated. If a threat substance is detected in elevated amounts, information about the type, location, time and amount will be registered and sent to a command central where further evaluation and appropriate actions can be initiated. The intention is to cover a large area that can be reduced step by step into narrower areas due to a positive alert. The number of sensors used will be increased in the smaller areas. For the final verification stand-off detectors in equipped mobile units will be used to pinpoint the location of the bomb factory. The techniques adopted in the project include electrochemical sensors for the sewage subsystem, resonant Raman and active QCL (Quantum Cascade Laser) transmission spectroscopic techniques for the area monitoring subsystem. Active imaging IR (Infra Red) laser backscattering and stand-off imaging Raman spectroscopic techniques will be used in the final verification. In the EMPHASIS project, threat analysis and search strategy, system network and integration, deployment, legal aspects, cost effectiveness and data fusion and information management will be evaluated. The project also includes a test and subsystem validation part. The consortium consists of eight partners, research institutes, an industry, SMEs and an end user.

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: SEC-2011.3.4-2 | Award Amount: 4.94M | Year: 2012

Border security is one of the key security challenges to be taken up by Europe in the following years. In particular, the deployment of practical efficient means to detect hidden persons and illegal substances at border crossing points is instrumental in avoiding terrorism, human trafficking or smuggling. The DOGGIES project aims at demonstrating (1) an operational movable stand alone sensor for an efficient detection of hidden persons, drugs & explosives, (2) the potential adaptation of this solution for the detection of a much wider range of illegal substances. The project addresses trace detection: it relies on the combination of two technologies based on completely different physical principles, therefore qualified as orthogonal: - Mid-Infrared spectroscopy technology, based on photoacoustic detection, which appears as the most powerful and promising to detect a very wide range of volatile organic compounds (VOCs); developments within DOGGIES will mainly target the demonstration of a widely tuneable integrated MIR source coupled with a miniature photo-acoustic cell; - Ion mobility spectrometry (IMS) technology, more mature, as mentioned above; developments within DOGGIES will mainly target the use of non radio-active ionisation source. One of the main operational challenges is to provide reliable detection in real environments, in particular with the presence of interferents. It is expected that the use of specific pre-concentrators on one hand, and the combination of the signal emerging from these orthogonal technologies by advanced software on the other hand will improve the detection reliability. The Consortium is composed of 14 partners from 5 EU countries, including 2 End-Users; the project activities will cover basic studies in physics and chemistry, as well as sensor engineering and field tests.

Haned H.,University Claude Bernard Lyon 1 | Pene L.,Institute National Of Police Scientifique | Sauvage F.,University Claude Bernard Lyon 1 | Pontier D.,University Claude Bernard Lyon 1
Forensic Science International: Genetics | Year: 2011

We propose to quantify the accuracy of a likelihood-based estimator that was recently proposed for the determination of the number of contributors to a DNA mixture, when genetic data alone is considered [H. Haned, L. Pène, J.R. Lobry, A.B. Dufour, D. Pontier, Estimating the number of contributors to forensic DNA mixtures: does maximum likelihood perform better than maximum allele count? J. Forensic Sci., in press]. Using Bayes' theorem, we derive a formula for the calculation of the predictive value (PV) of the likelihood-based estimator. The PV gives the probability that a DNA stain contains the DNAs of i people given that the maximum likelihood estimator gave an estimate of i contributors for this stain. We illustrate the PV calculations for two different types of DNA evidence: traces and body fluids. The PV varied according to the number of contributors involved in the DNA stain. Setting the maximum number of possible contributors to five, the lowest predictive values were scored for five-person mixtures with a minimum value of 0.26 for traces, but values were always above 0.94 for stains comprising one, two or three contributors, for both traces and body fluids. Values remained relatively high for four-person mixtures with a minimum value of 0.69. These findings confirm that likelihood-maximization is a powerful approach for the determination of the number of contributors to forensic DNA mixtures. © 2010 Elsevier Ireland Ltd. All rights reserved.

Negre E.,University Claude Bernard Lyon 1 | Motto-Ros V.,University Claude Bernard Lyon 1 | Pelascini F.,CRITT Materiaux Alsace | Lauper S.,Institute National Of Police Scientifique | And 2 more authors.
Journal of Analytical Atomic Spectrometry | Year: 2015

The analytical figures of merit of laser-induced breakdown spectroscopy (LIBS) for elemental analysis of glass have been evaluated using a laboratory prototype of the LIBS instrument for the quantification of 4 elements, Ti, Cr, Ca and Ba. Two sets of samples were prepared or collected for the assessment. The first one consisted of 10 laboratory-prepared fused beads with the elemental content determined by X-ray fluorescence (XRF), an established analytical technique which was considered in our study as the reference technique for the assessment of the LIBS technique. Among them, 8 were used as reference samples and 2 as "unknown" samples for test. The calibration curves were thus established with the references. The counter calibration led to the determination of the elemental content in the unknown samples. Such a calibration procedure allowed assessing the figures of merit of LIBS together with the used setup and measurement protocol about a certain number of key parameters, such as the correlation with a linear regression of the calibration data, limit of detection (LoD), repeatability, reproducibility and relative accuracy. The second set of samples was collected from different origins and consisted of 8 bottle glass fragments, which were different in appearance (color and surface) and in content for the 4 analyzed elements. Their elemental concentrations were first determined using XRF. The LIBS calibration curves established with the fused beads were thus used to perform the analysis of 2 glass fragments with elemental contents lying around the range of the calibration concentration. Further analysis of the ensemble of glass fragments allowed assessing the matrix effect introduced by the different types of glasses and extending the calibration curves over a very large concentration range from several ppm to several percent. We show that the self-absorption effect observed over such a large concentration range can be taken into account by using quadratic regression. This journal is © The Royal Society of Chemistry.

Debernardi A.,Institute National Of Police Scientifique | Suzanne E.,Institute National Of Police Scientifique | Formant A.,Institute National Of Police Scientifique | Pene L.,Institute National Of Police Scientifique | And 3 more authors.
Forensic Science International: Genetics | Year: 2011

Multivariate analyses of 205 positive control experiments in an AmpFℓSTR© Identifiler© STR kit were used to analyze the factors affecting peak heights at 16 loci. Peak heights were found to be highly correlated between loci and there was evidence for a difference in sensitivity of the two genetic analyzers in the blue channel. Heterozygous balance response at 10 loci was found to behave as a random variable following a beta-distribution with typical median values of 90%, without locus or genetic analyzer effect. Inter-locus balance at 16 loci was influenced by the blue channel effect and a temporal switch of unexplained origin. The implications of these results for the choice of minimum threshold values in quality control are discussed. © 2010 Elsevier Ireland Ltd. All rights reserved.

In France, according to the official statistics of the Home Office, we count in full year more than 100.000 hitand-run car offences after accident (135.147 in 2008 that is approximately 25% of the noticed road offences, representing the second source of offences after the driving under the influence of alcohol. To identify the runaway vehicle the Physics-Chemistry sections of the French laboratories of scientific police of the INPS (National Institute of Scientific Police) use various techniques of chemical analysis, as the infrared spectrometry. After analyses, the results are compared with those obtained for present motor vehicles in database of the automotive paints. This database arises from a fruitful collaboration which began in the middle of 1990s, between various European scientific laboratories of police. The implement of this ?chemical recording information? on the automotive paints is proving to be of a precious help in the ?demonstration of the truth".

Briant E.,Institute National Of Police Scientifique
Actualite Chimique | Year: 2010

The identification of persons for judicial purposes has been a great step forward with the establishment of anthropometric files by Alphonse Bertillon in late XIXth century. The discovery of fingerprints as individual mark allows Bertillon to create a schematic fingerprints database. The automated database will be created in France in 1987 ("Fichier automatisé des empreintes digitales", FAED). With the discovery of DNA in 1953 and the development of techniques for DNA analysis, techniques for identification evolve. Eleven years after the FAED, the national automated database of DNA fingerprint (FNAEG) is created in order to record genetic profiles of persons involved in sexual crimes. The Perben law of 2004, allowing the extension of crimes leading to the establishment of DNA profiles, increases the number of genetic profiles registered in the FNAEG. Today more than 1 240 464 profiles are registered and 58 378 comparisons have been made. This article aims to illustrate the implication of chemistry in the determination of a revolutionary scientific proof one century after the fingerprints: the DNA profiling.

Haned H.,CNRS Biometry and Evolutionary Biology Laboratory | Pene L.,Institute National Of Police Scientifique | Lobry J.R.,CNRS Biometry and Evolutionary Biology Laboratory | Dufour A.B.,CNRS Biometry and Evolutionary Biology Laboratory | Pontier D.,CNRS Biometry and Evolutionary Biology Laboratory
Journal of Forensic Sciences | Year: 2011

Determining the number of contributors to a forensic DNA mixture using maximum allele count is a common practice in many forensic laboratories. In this paper, we compare this method to a maximum likelihood estimator, previously proposed by Egeland et al., that we extend to the cases of multiallelic loci and population subdivision. We compared both methods' efficiency for identifying mixtures of two to five individuals in the case of uncertainty about the population allele frequencies and partial profiles. The proportion of correctly resolved mixtures was >90% for both estimators for two- and three-person mixtures, while likelihood maximization yielded success rates 2- to 15-fold higher for four- and five-person mixtures. Comparable results were obtained in the cases of uncertain allele frequencies and partial profiles. Our results support the use of the maximum likelihood estimator to report the number of contributors when dealing with complex DNA mixtures. © 2010 American Academy of Forensic Sciences.

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